Hydraulic torque wrench



April 16, 1946.

H E. PAGE HYDRAULIC TORQUE WRENCH Filed Jan. 22, 1945 ll lll'nllnlllll ll'lllll'lI'llIlll'l INVENTOR. iLEl'LDET'i Eat 15' Patented Apr. 16, 1946 UNITED STATES PATENT. OFFICE v 1 2,398,392 c HYDRAULIC 'roaoua WRENCH Herbert E. Page, Alhambra, Calif. Application January 22, 1945, Serial No. 574,001

Claims. (CL 81-523) v latter piston having threadedly mounted axially This invention has to do with wrenches, relating in its more particular aspects to wrenches for measuring the force of the torque applied in the tightening and loosening of nuts, studs and the like.

It is an object of my invention to provide a device of this character which accurately visually indicates the extent of the torque by bydraulic means.

Another object of the invention is the provision of a torque wrench which acts automatically to relieve the torque application when a predetermined point is reached.

A still further object is to provide in such a wrench novel means for delivering to the wrench head a series of hydraulically applied impacts to facilitate performance of the work being done by the wrench.

While my invention possesses still further objects and advantages, those will become apparent from the following description of apresently preferred embodiment which I have chosen for the purpose of explaining the invention, it being understood that within its broader scope as defined by the appended claims, the invention is capable of being embodied in other and modified physical forms which will be suggested by the following description to those skilled in this art.

For purposes of the following description I shall refer to the accompanying drawing, in which:

Fig. 1 is a side elevation;

Fig. 2 is an enlarged medial longitudinal section, partly in elevation, of the left-hand end portion of the device shown in Fig. 1;

Fig. 3 is an enlarged medial longitudinal section, partly in elevation, of the right-hand end portion of the device shown in Fig. 1; and

Fig. 4 is a section taken on line 4-4 of Fig. 2.

The numeral 5 denotes the body having an internally threaded bore 6 to receive the externally threaded handle portion 1, and having left-- hand end bifurcations 8 with a space 9 therebetween in which to mount the rock member generally indicated by the numeral l0, and a bore providing a cylinder Ii.

The rock member in has a transverse openin i5 of square cross-section in which fits the pivot member ii of square cross-section, which extends through round holes l'l in bifurcations 8. 0n the outer end of the pivot member is mounted a conventional work-connecting socketed member S for engagement with the work,

The body provides a cylinder or chamber is in which is threadedly mounted a piston IS, the

therein an auxiliary piston 20, said elements constituting maximum torque regulating 7 means.

' Mounted in the oppcsiteend of cylinder iii are pistons 22 and 23 urged apart by a spring 24, piston 23 seating againstjthe left-hand end of the cylinder.

A conventional gauge 21 of well-known construction communicatesby suitable connection line 28 with cylinder it, the fluid pressure in cylinder l -l acting upon a maximum torque indicating pointer 29 in the-gauge to indicate in as-, v

sociation with suitable gauge indicia on the dial of the gauge the maximum torque which the wrench is to apply. I

Reciprocably'mounted in cylinder ii there is a piston which is acted upon in response to the applied torque by a pair of rollers 32 carried by the rock member. Piston it forms with the cylinder II a pressure chamber 35', which chamber in effect includes the passageway 36 and a bore 31 provided-in the body and which will be referred to hereinafter.

Another piston 40 is reciprocably mounted in a cylinder ii in the body, the latter piston being urged to the left by a coil spring 53. The front face of piston 40 forms with the left-hand end of the cylinder a chamber 44 which communicates with chamber 35 through a passageway 46 past a poppet valve 41 and also through a passageway 49 past a poppet valve Ell, the latter valve being urged seated by a spring 5i. Poppet 41 is urged seated by fluid pressure in chamber 55 provided in the body.

A second torque-indicating pointer 51 in the gauge 21 is acted upon by the fluid pressure in chamber 35 through a suitable connection line 58. Inoperation the chambers i8, 35, 44, 55 are charged with hydraulic fluid and by screwing one or both of the pistons I9, 20 inwardly the desired pressure is built up in chamber IE to correspond with the maximumtorque pressure to be applied by the wrench. This pressure is communicated through line 28 to the gauge and is indicated by the pointer 28.

As the rock member it rocks in response to applied torque, the rollers 32 selectively engage the piston iii to push the latter inwardly of said chamber 35, the pressure in the latter chamber being communicated to the gauge through line 58 to actuate the pointer 51. If the torque pressure exceeds that for which the device is set, the poppet 41 will yield and move of! its seat against the pressure in chamber Eli,- allowing fluid in the chamber 35 to pass into chamber 44, thus moving In the operation of such a wrench it sometimes becomes desirable to facilitate, for instance, the loosening or tightening of a bolt or'stud by means of a series of blows or impacts against the rock member. I shall now describe pulsating means incorporated in my device for accomplishing this purpose. e

A casing 60 is threadedly mounted on the righthand end of the body handle, the casing containing a solenoid coil 62 having a core 63, movement of the core being yieldably opposed in each direction by means of the respective springs 64, 65.

Reciprocably mounted in a bore 10 in the handle there is a piston 1| whose right-hand end is adapted to be engaged by the left-hand end of the core 63. Alternating current is applied to the coil through wires 15 when switch H is closed, causing the core 63 to reciprocate rapidly, striking piston 1| which latter is returned by a spring 18. Piston H acts upon the fluid in bore 31, which bore is connected through passageway 36 with chamber 35, thus converting the inward movement of the piston ll into hydraulic impacts against piston 30 and thus to the rock member. The casing 60 has an end extension 19 threaded thereon which provides a handle extension 80.

Mounted in the packing ring grooves of the respective pistons I9, 20, 22, 23, 30 and 40, as well as in the poppet 41., I provide conventional fluidtight packing rings 90. A packing ring 9| is also mounted in the annular groove 92in handle 1.

I claim:

1. A torque-measuring wrench comprising a body presenting a pair of fluid chambers, a torque-actuated member carried by the body for movement relative thereto and being adapted for operative connection with the work, a piston movably mounted in the first chamber to create a predetermined pressure therein, a second piston reciprocably mounted in the second chamber, said second piston being reciprocable in response to movement of the torque-actuated member relative to the body to generate fluid pressurein the second chamber, and valve means operable in response to pressure in the second chamber in excess of the pressure in the first chamber to relieve fluid pressure in the second chamber.

2. A torque-measuring wrench comprising a body presenting three fluid chambers, a rock member pivotally carried by the body for rocking movement relative thereto in response to torque applied to the work, means for operatively conassociated with the necting the rock member with the work, a piston threadedly mounted in the first chamber and movable therein to create a predetermined fluid pressure therein, a second piston reciprocably mounted in the second chamber and being operatively engaged by the rock member whereby to be reciprocated in response to movement of the rock member and thereby to generate pressure in the second chamber according to torque applied to the work, valve means operable in response to pressure in the second chamber in excess of the pressure in the first chamber to pass fluid from the second chamber to the third chamber, piston means in the third chamber and spring means cooperating with the last-named piston when the pressure inthe second chamber is below that in the first chamber to return fluid from the third to the second chamber.

3. A torque wrench comprising a body, a torqueactuated member carried by the body for movement relative thereto, said member being adapted for operative connection to the work and movable in response to torque applied to the work, and means for successively impacting said member comprising a piston reciprocably mounted in the body for impacting engagement with said member and hydraulic means operatively piston to generate a pulsating fluid pressure against the latter. a I

4. A torque wrench comprisinga body, a torqueactuated member carried by the body for movement relative thereto, said member being adapted for operative connection to the work and movable in response to torque applied to the work, and means forsuccessively impacting said member comprising a piston reciprocably mounted in the body for impacting engagement with said member and hydraulic means operatively associated with the piston to reciprocate the latter, said hydraulic means including body walls providing a fluid chamber, a piston reciprocably mounted in the chamber and electrical means operatively associated with the latter piston to actuate the same.

5. A torque wrench comprising a body, a torqueactuated member carried by the body for movement relative thereto, said member being adapted for operative connection to the work and movable in response to torque applied to the work, and means for successively impacting said member comprising a piston reciprocably mounted in the body for impacting engagement with said member and hydraulic means operatively associated with the piston to reciprocate the lat ter, said hydraulic means including body walls providing a fluid chamber, a piston reciprocably mounted in the chamber, spring means urging the latter piston in one direction in the chamber, and electrical solenoid means having a reciprocable core engageable with said latter piston.

HERBERT E. PAGE. 

